25.4mm Dia., 3mm Thick, 8-12μm BBAR Coated, ISP Optics Germanium (Ge) Window

Name: 25.4mm Dia., 3mm Thick, 8-12μm BBAR Coated, ISP Optics Germanium (Ge) Window | AR812-GE-W-25-3
Brand: ISP Optics
SKU: 24-572
Price: £346.80 GBP

25.4mm Dia., 3mm Thick, 8-12μm BBAR Coated, ISP Optics Germanium (Ge) Window | AR812-GE-W-25-3

Stock #24-572 5 In Stock

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£346.80

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Qty 1+	£346.80 each
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Specifications

General

Type:

Protective Window

Model Number:

AR812-GE-W-25-3

Physical & Mechanical Properties

Bevel:

Protective as needed

Clear Aperture (%):

Clear Aperture CA (mm):

21.59

Diameter (mm):

25.40 +0.00/-0.13

Thickness (mm):

3.00 ±0.13

Edges:

Fine Ground

Knoop Hardness (kg/mm²):

780.00

Parallelism (arcmin):

Poisson's Ratio:

0.28

Young's Modulus (GPa):

102.7

Optical Properties

Coating:

BBAR (8000-12000nm)

Coating Specification:

R_avg <0.5% @ 8 - 12μm
R_abs <1% @ 8 - 12μm

Index of Refraction (n_d):

4.002 @ 11µm

Substrate: Many glass manufacturers offer the same material characteristics under different trade names. Learn More

Germanium (Ge)

Surface Flatness (P-V):

λ/10 @ 10.6μm

Surface Quality:

40-20

Wavelength Range (nm):

2000 - 14000

Material Properties

Coefficient of Thermal Expansion CTE (10^-6/°C):

6.1

Density (g/cm³):

5.33

Regulatory Compliance

RoHS 2015:

Compliant

Certificate of Conformance:

View

Reach 240:

Compliant

Product Details

Minimal Chromatic Aberration Due to Low Dispersion
Uncoated Transmission from 2 – 16µm
Available with BBAR or DLC Coating for 8 – 12µm
Due to material supply chain disruptions with germanium, there may be increased lead times and price changes on our germanium products. For more information, please contact our customer service team.
Edmund Optics has limited remaining inventory of this part number and no raw material available to supply more once this is depleted. Please contact our Product Support Engineers to help with an alternate solution for your needs. Customer Service can provide you the latest price and availability.

ISP Optics Germanium (Ge) Windows provide transmission and low absorption through the Long-Wave Infrared (LWIR) spectrum, making it useful for thermal imaging applications. Germanium features a Knoop Hardness of 780, making it ideal for infrared applications requiring rugged optics. These windows are available uncoated, Broadband Anti-Reflection (BBAR) coated for 8 – 12µm, or Diamond-Like Carbon (DLC) coated for 8 – 12µm. ISP Optics Germanium Windows are ideal for integration into thermal imaging systems, especially those that require rugged optics. Germanium is subject to thermal runaway, meaning that the transmission decreases as temperature increases. As such, these germanium windows should be used at temperatures below 100°C.

Special Handling

Germanium Optics Handling and Cleaning Guidelines

Germanium optics require special handling and cleaning procedures. Always wear gloves during handling to prevent contamination, and wash hands afterward. Avoid contact between Germanium dust and the eyes, skin, or clothing. When not in use, store optics sealed and covered at temperatures between 20°C and 25°C. Do not expose them to temperatures exceeding 100°C when in use.

Handling Guidelines

Always wear gloves to prevent damage from skin oils.
If Germanium dust is present, take the following precautions:
- Wear safety glasses to protect eyes.
- Use a dust mask or face mask to avoid inhalation.
- Wear gloves to prevent skin contact.
Maintain storage temperature between 20°C and 25°C with humidity below 30%.
Wrap Germanium optics in a lens cloth or pouch and seal in a container when not in use.
Germanium is brittle and heavy — always place it on soft surfaces and avoid dropping it.